[1] Northern inland waters emit CO 2 and CH 4 to the atmosphere but the importance of these emissions is poorly understood due to a lack of integrated catchment-scale estimates of carbon (C) emissions from lakes and streams. In this study we quantified the annual emission of CO 2 and CH 4 from 27 lakes and 23 stream segments in a 15 km 2 subarctic catchment in northern Sweden. All lakes and streams were net sources of C to the atmosphere on an annual basis. Streams dominated (96%) the aquatic CO 2 emission while lakes (61%) dominated the aquatic CH 4 emission. Total aquatic C emission from the catchment was estimated to be 9.1 g C m À2 yr À1 (98% as CO 2 ). Although streams only accounted for 4% of the aquatic area in the catchment, they accounted for 95% of the total emission. The C emissions from lakes and streams were considerably larger than previously reported downstream waterborne export of C from the catchment, indicating that the atmospheric losses of C in the aquatic systems are an important component in the catchment C balance.

Waterborne carbon (C) export from terrestrial ecosystems is a potentially important flux for the net catchment C balance and links the biogeochemical C cycling of terrestrial ecosystems to their downstream aquatic ecosystems. We have monitored hydrology and stream chemistry over 3 years in ten nested catchments (0.6-15.1 km 2 ) with variable peatland cover (0%-22%) and groundwater influence in subarctic Sweden. Total waterborne C export, including dissolved and particulate organic carbon (DOC and POC) and dissolved inorganic carbon (DIC), ranged between 2.8 and 7.3 g m -2 year -1 , representing~10%-30% of catchment net ecosystem exchange of CO 2 . Several characteristics of catchment waterborne C export were affected by interacting effects of peatland cover and groundwater influence, including magnitude and timing, partitioning into DOC, POC, and DIC and chemical composition of the exported DOC. Waterborne C export was greater during the wetter years, equivalent to an average change in export of~2 g m -2 year -1 per 100 mm of precipitation. Wetter years led to a greater relative increase in DIC export than DOC export due to an inferred relative shift in dominance from shallow organic flow pathways to groundwater sources. Indices of DOC composition (SUVA 254 and a 250 /a 365 ) indicated that DOC aromaticity and average molecular weight increased with catchment peatland cover and decreased with increased groundwater influence. Our results provide examples on how waterborne C export and DOC composition might be affected by climate change. Figure 4. Correlation coefficients for linear correlations (Pearson's r) between daily runoff and DOC concentration, a 254 , SUVA 254 , and a 250 /a 365 for ten nested catchments. Significance of correlation: *p < 0.01, +p < 0.05. Correlation analysis is using data from 2007 and 2008 jointly, n = 77-217. Catchment peatland coverage indicated in % below catchment notation 2289 WATERBORNE CARBON EXPORT FROM SUBARCTIC CATCHMENTS

Although CD133 has been proposed as a marker for brain tumor-initiating cells, studies show that a tumorigenic potential exists among CD133− glioma cells as well. However, it is not established whether the ability of CD133 − cells to form tumors is a property confined to a small subpopulation, rather than a common trait associated with most glioma cell types. Thus, we used lentiviral vectors expressing green fluorescent protein under lineage-specific promoters to identify CD133 − glioma cells expressing Nestin, glial fibrillary acidic protein (GFAP), and neuron-specific enolase (NSE). Flow cytometry analysis showed the presence of CD133 − subpopulations expressing these markers in glioma cell lines and in primary cultures from human glioblastoma (GBM) biopsies. Moreover, analysis of cell cycle distribution showed that subgroups expressing Nestin, GFAP, and NSE uniformly contained actively cycling cells, when cultured in serum-containing medium and stem cell medium. These subpopulations were fluorescence-activated cell sorted from CD133 − U373 glioma cells and implanted intracerebrally in severe combined immunodeficient mice. Moreover, we implanted Nestin-, GFAP-, and NSE-positive glioma cells sorted from a human GBM biopsy, following removal of CD133-positive cells. All the CD133 − subpopulations produced tumors, with no significant differences in survival or tumor take rates. However, there was a trend toward lower take rates for CD133 − glioma subpopulations expressing GFAP and NSE. These findings suggest that the ability to form tumors may be a general trait associated with different glioma cell phenotypes, rather than a property limited to an exclusive subpopulation of glioma stem cells. Cancer Res; 70(11); 4274-9. ©2010 AACR.

Urban flooding is of growing concern due to increasing densification of urban areas, changes in land use, and climate change. The traditional engineering approach to flooding is designing single-purpose drainage systems, dams, and levees. These methods, however, are known to increase the long-term flood risk and harm the riverine ecosystems in urban as well as rural areas. In the present paper, we depart from resilience theory and suggest a concept to improve urban flood resilience. We identify areas where contemporary challenges call for improved collaborative urban flood management. The concept emphasizes resiliency and achieved synergy between increased capacity to handle stormwater runoff and improved experiential and functional quality of the urban environments. We identify research needs as well as experiments for improved sustainable and resilient stormwater management namely, flexibility of stormwater systems, energy use reduction, efficient land use, priority of transport and socioeconomic nexus, climate change impact, securing critical infrastructure, and resolving questions regarding responsibilities.